. Principles and processes of electrical desalination of oil?

The principle of electrodesalination: The inorganic salts contained in crude oil are partially dissolved in the water present in the crude oil, while another portion remains suspended in the crude oil in crystalline form. The salts suspended in crude oil can be dissolved using fresh water; therefore, if the water is removed, the salts are also removed along with it. Thus, the problem of desalting crude oil is essentially a dehydration problem. Since the solubility of water in crude oil is very low, most of the water can be removed through static settling. A portion of it forms an emulsion with the crude oil, making it extremely difficult to remove; therefore, the problem of desalination and dewatering is essentially a demulsification problem. Emulsification is a process in which one liquid is dispersed as extremely small droplets within another liquid. The substance that causes oil to emulsify is an emulsifier. It is divided into \"hydrophilic\" and \"hydrophobic\" types; the former is soluble in water, while the latter requires demulsification in order to be dehydrated. Therefore, high-voltage alternating current is used in such devices. Under the influence of the high-voltage electric field, the emulsified oil causes the water droplets to develop induced dipoles or become charged with static electricity. As a result, forces act between the water droplets, increasing their speed of movement. When these droplets collide with each other, their kinetic energy and electrostatic attraction overcome the barrier posed by the emulsion film, allowing them to aggregate together. Once the water droplets rapidly coalesce and increase in diameter, gravity takes over, overcoming the force of the crude oil flowing from bottom to top, causing them to gradually settle at the bottom of the tank, thereby achieving dehydration.